DISQUS

koticka · 1 year ago

Result is predictable, this situation (raid controller) described in many documents about linux io scheduler. Scheduler (any) works only for hdd without any raid controllers.

Me · 1 year ago

echo 1 > /proc/sys/vm/drop_caches

Yordan · 1 year ago

Kernel version?

Kostas Georgiou · 1 year ago

Well there isn't much that the I/O schedulers can do if your access pattern is quite random beyond maybe giving you better average latencies .

Running cfq with slice_idle=0 might be a good idea btw, keeping the disks idle for up to slice_idle (8ms by default) isn't probably the best option for a db workload.

It would be interesting to get some plots/movies from seekwatcher also, I find that it gives you a nice insight on your workload and how each scheduler is affecting it.

Scoundrel · 1 year ago

2.6.18-53.el5

Yordan · 1 year ago

what is the number of threads in mysqld?

Scoundrel · 1 year ago

2Yordan: There were 8 separate threads in our "database load generation tool" (sphinx indexer) + some number of requests is being done from the site directly.

Marcelb · 1 year ago

Link to the conference:
http://video.google.com/videoplay?docid=-630496...

Илья · 1 year ago

Спасибо!очнь интересная статья!